/*const reg = /^[0-9a-zA-Z]{3,6}$/g;

let s1 = "123456";
let s2 = "a23456";
let s3 = "123";
console.log(reg.test(s1));
console.log(reg.test(s2));
console.log(reg.test(s3));

const reg = /日本|钓鱼岛|政府/g;

let str = "钓鱼岛是中国的，不是日本这个政府的，日本的政府新闻公告..."
const re = str.replace(reg, "**");
console.log(re);

const reg = /(\d)(?=(\d{3})+$)/g;
let str = "1234567890";
const re = str.match(reg);
console.log(re);[1,4,7]

const re = str.replace(reg, "$1,");
console.log(re);

*/